/* Copyright (C) 2007-2008  klevgert  http://code.google.com/p/db4o-netbeans/

This file is part of the db4o-netbeans module suite.

db4o-netbeans is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o-netbeans is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */


package com.db4o.nb.api;

import java.util.List;

/**
 * Encapsulates a constraint data object. 
 * @author klevgert
 */
public interface Constrain {
  
  /**
   * Gets the tag of the constrain (value, not, greater, smaller)
   * @return tagging of constraint
   */
  public String getTag();
  
  /**
   * Gets the java type encapsulated in the constraint.
   * @return java class as a string
   */
  public String getType();
  
  /**
   * Gets the value of the constraint. May be a name (in case of a descend) 
   * or a literal.
   * @return value of the constraint. 
   */
  public String getValue();
  
  /**
   * Gets sub constraints.
   * @return list of sub constraints.
   */
  public List   getChildren();
  
  /**
   * Adds a constraint to its children.
   * @param c   child constraint
   */
  public void   add( Constrain c );
  
  /**
   * Removes a constraint from the list of its children.
   * @param c   child constraint
   */
  public void   remove( Constrain c );

}
